I wasn’t sure where to post this. I’ve been liking what others have been doing with the Diamond Drag bits and saw a few people ordered their bits from Ebay. I decided to order a 120 degree spring loaded diamond drag engraving bit and the 90 degree replacement bit. I received the shipping notice the same day I ordered and then it actually shipped Monday and arrived Thursday. I opened the package to find a bag with a shiny nice looking tool and a pre installed bit with a blue cap. Another small bag had the additional bit with a black cap and a spring. I pulled the blue cap off the pre installed bit and noticed it was a bit less than a right angle even though it was supposed to be the 120 degree bit. I pulled off the black cap on the other bit and noticed it looked spot on at 90 degrees. I compared the two and came to the conclusion that the pre-installed bit is only 60 degrees. When I emailed the seller he responded that yes the pre installed bit was 120 degree and that “The one with the blue protector is 120 and black is 90. 120 is pointier that the 90.” I responded that I didn’t think that was right, that 120 is an obtuse angle. The last response ended with him telling me to send the it back that he wasn’t going to argue about the angle and whoever I buy from is going to tell me the same thing. He even pointed out that he had a diagram showing the angles, which in fairness I didn’t click on till today and it indeed shows 120 degrees being a sharper angle than his 90 degree bit. I appreciate that he’s willing to take it back, and his ebay page even says returns accepted. He’s got great feedback, and I don’t want to leave negative feedback. But I can’t believe that nobody else has noticed or questioned this before. Am I missing something, is there a alternate degree scale that I’m missing in relation to diamond drag bits?
My reasoning for ordering both 120 and 90 is for the thicker line that 120 is supposed to give in acrylic and glass and I figured 90 would be good for the harder materials. Is it worth keeping this, what I think is a 60 degree bit, or will it go unused? I know loaded question there, but what are others experiences with this pointy of drag bit?
Any help or comments would be appreciated. I’m confused.
This is the picture of the two diamond drag bits. Blue cap is supposed to be 120 deg and black cap 90 deg
Diagram from sellers ebay page.
C3D end mills showing their 90 and 60 deg end mills. C3D’s 60 is what the 120 deg bit I received looks like.